The present invention relates to a novel process for producing various gangliosides and analogues thereof which are expected to be used as medicines for curing dementia and anticancer medicines.
Ganglioside is a general term for sphingolipids having sialic acid and are given abbreviations such as GM1, GM2, GM3, GM4, GD2, GD3, GT2, GT3, and GT1b depending on their structures, especially sugar chain structures and they are widely present in living tissues of higher animals. Recently, gangliosides have been noted since it has been clarified that gangliosides have activity of an enhancement factor of proliferation and differentiation as acceptor molecules of hormones and bacterial toxin.
However, there have been very few examples of chemical synthesis of gangliosides and only a few reports have been made on synthesis of gangliosides, namely, synthesis of GM3 in Glycoconjugate J., 2, 5-9 (1985), synthesis of GM4 in Carbohydr. Res., 163, 209-225 (1987), etc. These known processes for preparation of gangliosides are very low in yield and are far from being put into practical use. Thus, development of a process for producing gangliosides and analogues thereof more effectively and in high yield has been desired.